Microscopic Measurement and Analysis of the Soiling Behavior of Surfaces with Standardized and Real Dust – A Parameter Study

Desert areas are noteworthy for solar system installation due to high yearly global irradiance. These arid regions bear extreme conditions for surfaces, like glazing and mirrors, of solar thermal systems. Surfaces are targets for soiling because of wind and high dust loads. Soiling is causing a decrease in transmittance that limits the overall performance. At a certain level depending on surface properties, like functionality and their reliability, is surface material soiling-prone. For surface qualification is a reproducible soiling test needed. An in-house developed artificial soiling device achieves this purpose. Realistic dust deposition is used to test the functionality and properties of surfaces for application in arid regions. The parameter study points out the connection between properties of surfaces and the adhesion behavior of real dust. Soiled surfaces are analyzed by by spectroscopic (FT-IR) and gravimetric measurements.